Lymphoid colony growth with phorbol myristate acetate and lymphocyte-conditioned media in chronic lymphocytic leukemia and malignant lymphomas.

Cell preparations from 49 cases of lymphoid malignancy were cultured to determine optimal culture conditions (in semisolid media). Colony growth was obtained in the majority of cases (73%) using the combination of phorbol myristate acetate (PMA) and lymphocyte-conditioned medium (L-CM). Cell surface marker studies of plated cells in 36 cases identified 31 to be B-cell type, 1 to be T-cell type, and 4 null-cell type. The morphology and markers of harvested cells were similar to plated cells, suggesting proliferation of neoplastic cells predominantly. A relationship was found between the degree of colony growth and the clinical course of the disease in lymphomas but not in chronic lymphocytic leukemia (CLL). The use of PMA in combination with other mitogens deserves further investigation as a colony growth stimulator in hemopoietic malignancies.